Staun Tyre Deflators are the easiest, most reliable way to deflate tires for increased traction off-road. Simply screw the deflators onto any standard tire valve system to automatically deflate each tire to your preset pressure. Each deflator automatically shuts off at a preset pressure that can be adjusted between 6 to 30 PSI to suit your specific vehicle and terrain. Presented in a leather case, and preset to 18PSI, these are perfect for the every day off-roader